Enhancing ion transport in nanofluidic systems through counter-charged nanochannels

Abstract

In this work, we propose a new strategy to enhance ion transport in nanofluidic systems using counter-charged nanochannels, where half of the channels are positively changed while the other half are negatively charged. Molecular dynamics simulations and experiments are conducted to demonstrate the idea. Simulations show that the ionic current for the proposed system can be 5.8 times higher than that in the traditional fluidic systems, i.e., uniformly charged systems. The enhancement is caused by the separate transport of cations and anions in negatively and positively charged channels, respectively, for which the effective energy barrier for the ion transport is low. Experiments are carried out to confirm the proposed method. The results in this work provide helpful information for the design of certain energy systems, such as batteries and electrodes.